Serum vitamin D levels and Sjogren's syndrome: bi-directional Mendelian randomization analysis

• Published in: Arthritis research & therapy 2023-05, Vol.25 (1), p.79-79, Article 79
• Main Authors: Zhao, Meng, Wei, Feiran, Li, Han, Wang, Zemin, Wang, Shuai, Liu, Yangyang, Fei, Gaoqiang, Ge, You, Wei, Pingmin
• Format: Article
• Language: English
• Subjects: 25(OH)D; Arthritis; Autoimmune diseases; Cross-sectional studies; Genome-Wide Association Study; Genomes; Humans; Mendelian randomization; Mendelian Randomization Analysis; Methods; Nonoxynol; Observational studies; Polymorphism, Single Nucleotide; Sample size; Sjogren's Syndrome - diagnosis; Sjogren's Syndrome - genetics; Sjogren’s syndrome; Statistical power; Vitamin D; Vitamin deficiency
• ISSN: 1478-6362; 1478-6354; 1478-6362
• DOI: 10.1186/s13075-023-03062-2

Based on the results of existing observational studies, it can be found that the association between serum vitamin D levels and the risk of Sjogren's syndrome (SS) in humans is still controversial. Based on this situation, this study aimed to assess the causal relationship between serum vitamin D levels and SS by using the Mendelian randomization (MR) approach. In this study, genome-wide association studies (GWAS) summary statistics on serum vitamin D levels [sample size = 417,580 (UK Biobank)] and SS [sample size = 416,757 (cases = 2495, controls = 414,262) (FinnGen)] were used. The bi-directional MR analysis was then used to assess possible causal relationships. The major analysis method of MR was performed using inverse-variance weighted (IVW), supplemented by MR-Egger and the weighted median approaches. In addition, sensitivity analyses were used to ensure the stability of the results, including Cochran's Q test, MR-PRESSO, MR-Egger intercept test, and the leave-one-out test. The MR suggested that no significant causal effects of serum 25(OH)D levels on SS risks were observed [odds ratio (OR) = 0.9824; 95% confidence interval (CI) = 0.7130 to 1.3538; P = 0.9137]. Similarly, no evidence supported the causal effects of SS on serum vitamin D levels (β: 0.0076, 95% CI: - 0.0031 to 0.0183; P = 0.1640). This study found no obvious evidence that serum vitamin D level is causally associated with SS risks or vice versa. We call for larger sample size studies to further unravel the potential causal relationship and the exact mechanism.